Pneumat



I. B. ZIIVIDARS.

PNEUIVIAIIC TIRE.

APPLICATION FILED SEPT. 7,19I7.

Patented Oct, 28, 1919.

rm: unumnn PLANOGRAPU en., WASHINGTON, Da c.

starr-nn srnrns Parana onirica JI-IN B. ZIMDARS, OF `SAN FRANCISCO, CALIFORNIA.

citizen of the'United States, residing at San` PNEUMATICl TIRE.

Specification of Letters Patent.

VApplication*filed September 7, 1917. Serial No. 190,108.

To allwkomz'may concern.' Y

-Be it known thatLJoHN B. ZIMDARS, a

Francisco, in the county of San VFrancisco and State of California, have invented new and useful Improvements` in `Pneumaticv Y `Tires, of which the following isa `specification.

The object of the present invention isto provide a permanent metallic structure con- Y Vstitutin'g an inner arc ofthe outside casing or shoeV of a pneumatic or other tire andk improved `means for fastening the outside shoe or casing thereto. A In the accompanying drawing, Figure 1 i abroken perspective view of aV tire thus improved, and of a permanent'hollow metallic ring forming an inner arc of the casing or shoe; Fig. 2 is asimilar view on afreduced scale, showing also part of the wheel.

`Novel features herein disclosed' but not claimed are claimed in coepending applications which are divisions hereof.

Referring to the drawing, 1 indicates one a rim 2 having on 'one side an outwardly eX- tending iange 3. `Around said are arranged the twolsections 4 of a hollow sheet Y soV metal ring.` The hollow sections 4 have inner edges 7 abutting against each other, and broad outer edges 8 which extend, ingeneral" j direction, in planes transverse tothe `ams of the lwheel, and each section has an inner cylindrical side Eil-contactingV with the cy#` lindrical surface ofthe rim and an outer side 6, which is concave in cross-section, so that thegsides 6 of thetwo sections, of the 'i i metal ring have a substantially semi-circular form in cross-section. l A Said ring sections 4 are secured together by long bolts 9, the headsl() of which are received in a lgroove 11` in theouter wide edge 8 of one ring section 4, while nuts 13 are screwed'upon4 the 'other ends of said bolts and are received in a corresponding groove V14V in the wide edge 8 of the other ring section 4. v

Surrounding the hollow ring sections 4 and received in the concave outer sides 6 thereof is an endless pneumatic tube 16 of canvas, inflated in theusual manner, having` a thin inner facing 17 of soft` rubber and secured to a thick outer coating 18 of a portion thereof, also of soft rubber. which varies greatly in thickness. The coating 18 does not extend completely around the tube 16 and it is not interposed between the tube 16 and the hollow ring sections 4. but it begins on each sideof the tube 16 where the sides of said tube leave the ring sections 4 and fits in the space between the sides of tube 16 and the side portions of a tread or casing 19.

Said casing 19 is secured to the ring sections 4` in the following manner. Each ring section is formed in its wide side with a circular groove 21, and the edges of the casing are` formed with beads 22 of metal orother rigid material, vwhich enter said grooves. They are retainedtherein by means of rings 23, which'aresecured to the wide edges 8 of the ring sections '4 Vby screws 24, and which havel inwardly extending portions 26 fitting4 tightly in said grooves 21 and wedging the beads therein and outward eXtensions 27, which overlap the inner edges of the casing and retain its inner edges inthe grooves 21. The casing is formed with a tread 28 having, embedded in rubber, layers ofcanvas 29, and similar in general character to those at present in use.

Between the tread and the pneumatic tube is interposed a protecting ring 3l. This ring comprises, in order proceeding from the outside inward, first, an outer ring 32 of soft rubber, then a circular series of rectangular protecting blocks '33,. (with edges rounded off) and their longer measurement being crosswise of the tire, these blocks being of wood or other impenetrable material, spaced slightly from each other, then an inner ring 84 of soft rubber, then another series of blocks 86 of impenetrable material Said-rings 32, 34, 35 are all connected with eachother at the edges, so that the blocks 83 and 36. are completely inclosed, and said rings and blocks Yare all cemented together by rubber. The blocks of each `series are staggered relatively to those of the other series, so that the spaces between the blocks of each series register with the central portions of the blocks of the other series. It will thus be seen that it is impossible for a nail orV other sharp instrument to penetrate through bothseries of blocks. The blocks of the inner series are preferably convex so as to be thickest toward the center of their longer measurement, but also slightly concave at the centers of their inner surfaces, as shown at 37, and all the blocks, both at their ends and at their edges where they are spaced from each other, are rounded so as to avoid any cutting of the rubber in Contact therewith. The rubber intervening between the inner tube 16 and the casing 19, or between the inner tubes and the blocks 36, varies greatly in thickness, being thinnest next to the middle portions of the sides of the tube 16 and thickest next the ends of the blocks 36.

It will be seen that my improved tire is not subject to punctures such as are common with ordinary pneumatic tires, and that the only part exposed to wear is the tread, which can be renewed at a comparatively low cost when worn out.

The blocks 36 of the inner series have fluted portions, the purpose of which is to take up slack in the periphery of the inner tube 16 which exists when said tube is not fully inflated, so as to assume a circular form; the convex shape of the inner series of blocks is to provide greater and quicker resiliency when pressed against said tube 16. When the tube is fully inflatedit will assume a substantially circular form in crosssection, as shown in dotted lines.

" lt will be seen that my invention dili'ers from prior constructions in that the pneumatic tube is' inexpansible as distinguished from'the soft rubber tubes heretofore used for pneumatic tubes. When inflated it assumes a form as nearly as possible circular in cross-section which, by thereby increasing the area within the tube, takes up all the slackin the cavity left between the flexible shield and the rim.

1t will be observed that my invention differs from ordinary pneumatic tires in that there is interposed, between the inner tube and the tread of the tire, material that is, for the most part, inelastic, as contrasted with the large amount of rubber used on the outside or inside of the tire in some present day constructions. The contraction and expansion of this rubber in these old constructions, relieves, to a certain extent, the inflated inner tube of its work in contracting and expanding, but with a greater loss of energy, on account of the fact that air can contract andexpand much more readily and with much less loss of energy than solid elastic material. Consequently, it is an adi vantage that no attempt should be made to `thrown upon the elastic air within the inner tube, and this 1 accomplish in my invention by interposing as much as possible only inelastic material between the inner tube and the outside of the tire,l the intervening portions of rubber only being of sufficient thick-v ness to form a container for the different pieces of impenetrable material to hold the same in their proper relations and to render the shield flexible, in a circumferential dif rection, Vthus constitutingfa single, flexible, continuous, annular belt.

Another purpose of my invention is to provide a tire that will not require an outer casing with stiifheavy sides as those of the 'foV casings'in present use or with sides extend- Y ing inwardly so that they in themselves form the circle inclosing the yinner tube, or

with the heavy clencher or heavy bead construction; but which will instead permit of tube, and are there removably fastened to the metal tire section, thus providing a highly iexible and inexpensive and easily replaceable wearing shoe.

, 1 claim: A

l. A demountable rim, comprising two hollow metallic sections separable circumferentially, and bolts holding the sections together, said sections having their inner surfaces flat transversely, and their outer surfaces forming transversely an arc of a circle. Y

2. A demountable rim, Vcomprising a hollow metallic section, having a flat inner periphery, and its outer periphery forming transversely an arc of a circle, and having on the outer sides of the outer periphery grooves to receive the beads of the inside periphery of the tire or shoe which forms the remainder of the circumference of the tire, and detachable rings bolted over the said grooves and holding the said beads secure in the said grooves.

3i. B. ZiMnA'Rs;

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C. 

